In-flight performance of the SBS-1A solar array featuring ultrathin, high efficiency solar cells

Ultrathin (0.0025 inch) solar cells were selected for use on the Satellite Business System (SBS) 1A solar array, launched in September, 1988, to achieve minimum solar array weight and maximum end-of-life solar array power. The design of the ultrathin cell was predicted to produce an improved resistance to radiation degradation and superior current collection efficiency, thus increasing the power per unit area at end of life compared to conventional thickness silicon solar cells. The ultrathin solar cells were qualified for flight and characterized prior to fabrication of the SBS-1A array. Performance predictions in the mission environment were based on these characteristics and by the measured photovoltaic output of the flight solar cells. The predicted solar array performance has been validated to date within two percent by in-flight test data